The point Px 725 is on the unit circle in Quadrant IV Find

The point P(x, - 7/25) is on the unit circle in Quadrant IV. Find its x - coordinate.

Solution

Solution:

As we know in fourth quadrant :

x is positive and y is negative.

hence;

rcos = x and rsin = -7/25 (here in case of unit circle r = 1 unit)

as we know;

cos² = 1- sin²

=> cos² = 1 - 49/625

=> cos² = 576/625

=> cos = 0.96

=> x = 0.96 units